Primer chamber for fuses



June 9, 1925. 1,541,381).

0. H. PEARSON PRIMER CHAMBER FOR FUSES Filed June 15 "1,923

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Patented June 9%, 125;

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Application filed rune 13, 1928. Serial No. 645,046.

To all whom it may concern."

Be it known that I, Cs H. a citizen of the United States, and resident of Brookline, in the county of Norfolk. and

State of Massachusetts, have invented an Improvement in Primer Chambers for Fuses, of which the following description, in connection 'with'the accompanying drawings, is a specification, like letters on the rawings representing like parts.

My present invention relates to fuses, and

I more particularly to mechanical time fuses for use in connection with explosive shells and the like.

In mechanical time fuses, where the time of detonation of the charge of the shell is determined by a timing mechanism set in operation by the discharge of the shell from a gun, the operating parts are necessarily 0t delicate construction and yet such construc time must be substantial enough to withstandthe' tremendous shocks to which they are subjected. In addition, such operating parts must be associated with and surrounded by safeguards to ensure positive safety to the operating parts, the shell to which they are attached, and particularly to the operator who must handle them. In application Serial No. 419,3?1, filed Qc'tober 25, 1920, in the names of Charles H. Pearson and F. W. Bold, and in application Serial No. 426,406, filed November 26,1920, in the name of Charles H. Pearson, there are disclosed mechanical time fuses in which the most exacting requirements are complied with.

Because the operating parts and safety devices are of such necessarily delicate construction, and so essential to the success of modern gunnery, itis essential that such mechanism be subjected to the least possible handling or adjusting, and the goal of all inventors in this line of endeavor is the production of a mechanical time iuse'in which,

once the various elements comprising the same have been assembled, needfnever be removed from their position. As a step in this direction, the improved mechanism for allowingwinding of the timing gear, or'test- 11k ing of the condition of such gear, from the base of the fuse, and shown and claimed in the application of Charles H. Pearson and F. W. Bold, Serial No. $19,371, above referred to, is or" special importance, As both Pearson,

the mechanical timew fuses and the shells to which they may be attached are liable to be stored for long periods of time before use for the insertion of the primer, with the consequent possible derangement of the various operating parts and the increase of danger to the fuse and to the operator. As an improvement over the apparatus for winding the timing train shown and described in the co-pending application, Serial No. 419,371, above referred to, I have de--= vised means whereby the passageway er tending between the detonating chamber and the timing train is permanently closed, while yet making it-possible to wind the timing train from the detonating chamber.

With a view to overcoming the objections incident to dismantling thefuse, if have devised the subject matter of the present invention, wherein means is provided for installing the primer and detonating charge in the fuse without disturbing the operating parts of the fuse in any way, I accomplish this desirable result by the additionmf a separate primer chamber in which the primer and primer charge may be inserted and the chamber then placed into operative position with respect to the tg gear and firing pin from the base of the fuse. Such primer chamber may be associated with the iuse empty, and when the fuse is to be used, may be removed therefrom, the primer and primer charge inserted, and the primer chamber a ain associated with the f or such ch r may be associated with the fuse only at the time such fuseis to be used.

The principal ,object of my invention therefore, is an improved primer holg means for mechanical time fuses and the e. v other object is an improved mechanical time fuse in which'the primer may be associated with the timing gear.v at any te without disturbing the adjustment of such Other objects and novel features of the construction and arrangement of the parts constituting my improved device will appear as the description of the invention progresses.

Referring to the accompanying drawings,

Fig. 1 is an elevation, partly in section,

'of a mechanical fuse to which my invention has been applied;

Fig. 2 is an elevation of one form of my improved primer chamber;

Fig. 3 is an elevation of another form of my improved primer chamber;

Fig. 4 is an enlarged sectional view of a portion of a mechanical fuse showing that form of my invention illustrated in Fig. 2, in position;

Fig. 5 is an enlarged sectional View of a portion of amechanical fuse showing that form of my invention illustrated in Fig. 3, in position;

Fig. 6 is a bottom plan view of either Fig. 2 or Fig. 3, and r Fig. 7 is an enlarged sectional View of a portion of a mechanical fuse showing an improved means for winding the timing train.

Referring to the drawings, 10 designates a fuse base to which is rotatably attached a setting cap 11, a compression ring 12, attached to the setting cap 11 and fitting into the circumferential groove in the base 10, acting as means for adjusting the freedom of rotation of the setting cap on the base. The setting cap 11 is utilized'as a protecting means, and as an adjusting means for the timing gear of the fuse, said timing gear being shown in dotted outline at 13. This timing gear 13 controls the operation of the firing pin 14, in alinement with which is a passageway 15 in the base 10 leading to the detonating chamber 16, the lower end of which chamber is threaded to receive a plug (not shown). Referring to Fig. 4, this passageway 15 is comprised of a straight portion 17 and a threaded portion 18, and is adapted to receive the primer chamber illustrated in Fig. 2, in which the portion 19 fits in the straight portion 17 and the threaded portion 19 ts in the threaded portion 18, or, referring to Fig. 5, the passageway 15 is comprised of a straight portion 21, adjacent the top of the base 10, an intermediate threaded portion 22 and a straight portion 23 adjacent the detonating chamber 16, and is adapted to receive the primer chamber illustrated in Fig. 3, in which the straight portion 24 fits in the straight portion 21, the intermediate threaded. portion 25 in the intermediate threaded portion 22 and the straight portion 26 in the straight ortion 23. In both forms of the primer 0 amber there is a seat 27 for the primer 28, a passage 29 leading from' the seat 27 entirely through the chamber and communicating with the detonating chamber 16, this passage being packed with pellets of powder. The lower end of the chamber is slotted at 30 to receive a screw driver or other suitable tool used for placing the chamber in pos1- firing pin 14. The seat 27 is slightly deeper than the length of the primer 28 so that there is no danger of premature discharge thereof by reason of contact with the plate 32. ,In the base 10, diametrically opposite the passageway for the primer chamber, is a passageway 33, the lower end of which is threaded to receive a plug 34, this passageway being utilized to reach the winding means for the timing gear 13, as shown and described in the application Serial No. 419,371, above referred to.

Referring now to Fig. 7, 37 designates a passageway through the base 10 and connecting the detonating chamber 16 with the top of the base. This passageway is counterbored top and bottom, as shown, the top to receive the enlarged end 38 of a member 39 that is rotatably mounted in the passage way, while the bottom receives the annular member 40 that slips over the lower end of the member 38, this lower end being upset or swaged at 41 in'the countersunk end of the member 40. Extending a-xiallyu ward in the member 39 is a. hole 42 and 'exten ing diametrically of this hole, and in the lower, face of the member 39, is a slot 43 adapted to receive a member 44 that extends transversely through a winding key 45. The end of the key 45, adjacent the member 44, fits into the hole 42, while the other end is provided with an enlarged knurled head 46 and by means of which the member 39 is rotated. In the upper face of the enlarged end 38 is formed a noncircular socket 47 that is in permanent engagement with the non-circular end of the staff of the winding train. It is obvious from the above description that the winding train may be wound from the lower or detonating, end of the base 10, and that also there is no open passageway between the detonating chamber 16 and the timing train. For convenience, the slot 43 and hole 42 are the same size as the slot 30 and hole 29 respectively, in the (primer holder so that the flan}? tool or win ing key may be used for With either form of my improved device, the entire comprising thefuse aaaaseo may be assembled either with or without the riming chamber and primer 28. Assuming that it is desired to store the fuses for a long period of time, or ship them; a long distance, the mechanical time fuse is preferably assembled without the priming chamber. The timing gear 13 however, and all parts associated therewith, are preferably adjusted at the time of assembly, and thereafter need not be disturbed in any way. \Vhen it is desired to place the fuse/in condition for use, preparatory to attaching the same to a shell, the plug (not shown) s retiming train mounted thereon, a detonating moved from the bottom of the base 10 and a primer chamber, with primer 28 positioned therein, such as illustrated in either Fig. 2 or Fig. 3, depending on the character of the receiving hole therefor in the base, is screwed into position, as shown in Figs. 4 and 5, the

passageway 29 filled with powder pellets, the detonating chamber 16 filled with powder, and the plug (not shown) replaced. Should the primer 28 fail for any reason, or doubt exist in the mind of the operator as to the condition of the primer, such primer is readily renewed or inspected, without the necessity of dismantling or disturbing the timing gear in any way.

The overall length of either form of the primer chamber may less than the length of the passage from the top of the fuse base to the primer chamber 16, and in some instances it is desirable to enlarge the lower end of such passageway, which enlarged end,

being filled with powder, adds to the effeciency of the shell.

While I have necessarily described the preferred embodiments of myinvention somewhat in detail, it is to be understood that I may vary the size, shape, and arrangements of the parts comprising my invention without departing from the spirit of the invention.

Having thus described my invention, what I claim as new is:

1. In a fuse, the combination of a base, a timing train mountedthereon, a firing pin controlled by said timing train, a removable primer holder mounted in the base in alinement with the firing pin, and a safety plate interposed between the,firing pin and the primer holder.

2. In a fuse, the combination of a base, a

chamber formed in the bottom of the base, a passageway leading from the detonating chamber to the timing train, a removable primer holder located in said passageway, and a safety plate normally located between the primer holder and timing train.

'3. Ina fuse, the combination of a base, a timing train mounted thereon, and means rotatably mounted in the base and associated with the timing train whereby the tim ing train may be wound from the bottom ofthe base.

4. In a fuse, the combination of a base, a timing train mounted thereon, and provided with means for winding the same, said base being provided with a passageway in alinement with said winding means, a closure for said passageway rotatably mounted therein, and associated with said winding means, and means for rotating said closure to wind the timing train from the exterior of the base.

In testimony whereof, I have signed my name to this specification.

CHARLES H. PEARSON. Witnesses: JAMES R. Honnnn, FREDERICK W. Bonn. 

